Trestle boat-davit of the rotation and gravity type



P 1953 D. BARRICELLI 2,650,377

TRESTLE BQAT-DAVIT OF THE ROTATION AND GRAVITY TYPE Filed June 30, 1949 IN VENTQR DOMEN/CO BARR/CELL/ Patentecl Sept. l, 1953 TRESTLE BOAT-DAVIT OF THE ROTATION AND GRAVITY TYPE Domenico Barricelli, Genoa, Italy Application June 30, 1949, Serial No. 102,251 In Italy August 12, 1948 6 Claims.

The present invention relates to boat lowering gear and is particularly directed to a davit, preferably used in pairs, and serving to support a boat, for example, a life boat, in an inboard position and movable to an outboard position to permit the boat to be launched either manually or by the operation of a winch or other mechanism.

An object of the present invention is to provide an improved boat davit of the kind pivotally mounted at its lower end for swinging movement between inboard and outboard positions which is simple in construction and movement, relatively light in weight, and certain and reliable in its launching operation even when the ship on which the davit is mounted is listing severely or on its beam ends.

Another object is to provide a boat davit of the described character which is constructed so that the weight of the supported boat is employed in effecting initial swinging movement of the davit to its outboard or launching position.

Still another object is to provide a boat davit of the described character which is constructed and arranged so that the space around the davit is relatively unobstructed thus making it possible to locate the davit at any point at the side of the deck without interfering with free passage or use of the adjacent deck space.

- A further object of the present invention is to provide a self contained boat lowering gear having the described characteristics so that the gear may be mounted as a unit in place of existing devices without requiring excessive alteration of the ship structure.

In accordance with the present invention, the above, and other objects, features and advantages, are accomplished by providing a boat davit which includes an outwardly curving beam pivotally mounted at its lower end adjacent the side of the deck for swinging in a vertical plane. A triangular trestle or strut is pivotally mounted at its base for swinging about an axis disposed outboard and parallel relative to the axis of swinging of the davit beam. The triangular trestle, at its apex, pivotally supports a guide block which is permanently connected to the davit beam for sliding along the latter and engageable with spaced stops on the beam for limiting the inboard and outboard positions of the lattter. A single fall or rope is provided for the dual function of controlling the position of the trestle or strut relative to the davit beam and hence the position of the latter, and for hoisting and lowering the boat supported from the free end of the davit beam. Further, the boat davit embodying the invention includes a lever member formed 7 with two angularly related arms and pivotally mounted at the junction of such arms on the swinging axis of the davit beam. One arm is formed to engage under the supported boat in its inboard position while the other arm engages against the davit beam in the outboard direction to urge the beam outwardly in response to the weight of the boat on the first mentioned arm.

These and other objects, features and advantages of the present invention will be apparent in the following description of preferred embodiments which is to be read in connection with the accompanying drawing forming a part hereof, and wherein:

Fig. l is a diagrammatic side elevational view of a boat davit embodying the present invention and shown in its inboard position;

Fig. 2 is a front elevational view of a triangular trestle or strut forming a part of the boat davit of Fig. 1;

Fig. 3 is a fragmentary sectional view along the line 33 of Fig. 1 and showing the structure for slidably connecting the trestle of Fig. 2 to the davit beam;

Fig. 4 is a diagrammatic side elevational view similar to Fig. 1, but showing the davit in an intermediate outboard position; and

Fig. 5 is a diagrammatic side elevational view similar to Figs. 1 and 4, but showing the davit in its fully extended outboard position with the lowering of the boat having been commenced.

Referring to the drawing in detail, and initially to Figs. 1, 4 and 5 thereof, a boat davit embodying the present invention is there shown to include a davit beam 1 pivotally mounted at its lower end for swinging in a vertical plane about an axis 2 disposed close to the supporting deck and at a suitable distance from the rim of the latter. At least the upper portion of the davit beam is curved or bent in the outboard direction so that a boat l3 supported by a fall I 0 suspended from the upper end of the beam I will clear the lower portion of the davit beam even when the latter is in its extreme inboard position (Fig. 1) A trestle or strut 4 of triangular shape (Fig. 2) is pivotally mounted at its base for swinging about an axis 5 disposed parallel and outboard relative to the axis 2 about which the davit beam swings. A slide member 3 is pivotally mounted on a pivot pin or axle 2| at the apex of the triangular trestle ti and slidably engages the beam l for movement along the latter. As seen in Fig. 3, the beam l is preferably formed with a flange extending along at least its outthe stone, respectively} 1 1 stops or abutments B and l are fixed on the beam I in the path of movement of the slide member 3.

As seen in Fig. 1, the stop 6, disposedbelow slide member 3, is engaged by the'latter when the beam I is in its extreme inboard position and. prevents further downward movement of the member 3 and hence further inward swinging of -the davit beam. As seen in Fig.3, the stop I, disposed above the slide member, engaged by th'e latter'when the beam is in its 'extreme-=outboard position and prevents further movement ofthe member 3 toward the top of the 'beam-and -hence further outward swinging ofthe davit beam.

The fall II! is connected at one end 'to the upper or freeendof the davit be'am I' 'and passes through a sheave "b lock' from-wliiclitheboat I3 is suspended. "'The'fal-l I ontihuestrom the sheave block and passes over a iaii lead or pu'lley I I rotatabl'ymounte dadjadenfi- 'th free end of the beam I. nominates-nae I-I,=thefali Ifiextends along the-'curved l'ength of 'the beam I-and is guided by fair'le'ads IB-and I 'i whioh a'rerotatably mounted on the beam I at p'oints onthe latter adj acent the center and immediately: below pulley I8 -is-rotatab1y mounted onthe trestle '5 adjacent the ape'x'or upthe axes of the pulleys or fair leads wane-18am between theaxis of pulley I8 and-axis-2',about which the beam {I swings, are respectively lengthened. The fall I It passes around and under" the fair lead I1 and thence over and around the pulley IS on the trestle.-'* Finally, a pulleybr fair 4 the boat on the arm 8 will cause the latter to rock in the clockwise direction, as viewed in Fig. 1, and the arm 9, formed integral with the arm 8, will urge the beam I in the outboard direction to initiate swinging of the davit beam to its outboard or launching position. This action of the lever member formed by the arms 8 and 9 ensures proper functioningv 'oftherdescribed boat davit even' when the-ship,--on which the latter is mounted, is keeled over in the direction away from the edge of the deck adjacent the davit.

-,1 -Since theIdavit-beam I curves or is bent in the z: outboard direction, it is apparent that the weight of the boat, substantially centered on a vertical -line extend-ing through the free or upper end of beamv I-,-.will..produce a turning moment about 'vth'e' axis 2 even after the keel I2 of the boat has been released from contact with the arm 8. This turning moment will cause the beam I to swing in the outboard direction and such swinging of thebeam will bewcommuhicated to 3 16 e i i fi 4 1 to effect movement ofthe slide :member 3- -,upwardly along-the beamand extension oii h-firdistance between theaxes oithe pulleys I= 'I and I8 binedresistance toturning of. thepulleysli; I6 and I'Iand of .the. sheave bloclmsupportingwthe 'boat is greaterqthansthe.frictional,uresistance to I sliding of themember 3,.the payedzout fall or, line I0 is initially taken up in the;lengthened-. passes ofrthe fall or line betweemthexpulley I.Ii;and-..-the

pjpulleys I'|..and I9, andzthereforemheiboat sub- I stantantially' retains. its initial position, withmespeot tothe upper-.end oi,.-the-.davit beam, .during the initial outboardswinging ofo'the Idavit beam, as shown in Fig. 4..?:When'-.the.davit beam reaches its extreme .outboard'position, asdetermined by. engagement ofnthetslidepmember 3 per'end of th latter sothat, asthabeam I s'wings in the outboard direction, the distances between against :thev upper. stoppl' (-Fig. 5);: the rpayedrout lineican no.;longer be: taken up by extension of the distancesbetween-theaxis of.-thetpulley I8 .and'the axes of the pulleys I Land I;9;.iaI-id the v weight of the boat cannotefiectanyviurtheriout- ".ward swinging ofxthe davit beam so that; such lead I9 is mounted for rotation about the" axis 2 close to the deck; about which thebeani-swings, and the fall II) is led"from"the pulley IQ-under the pulley I9, as at 20, a'n'd t'henc'eto 'a-device (not shown) for reeling iii'orpaying' out theiallfline, which device may be a manualor powered winch or other suitable mechanism mounted on the beam I itself or on adjacentstructure. At-"this point it should be noted'that'the combined resistance to turning of the pulleys or fainl'eads weight is then-zwhollyxoperative tohlowermthe sheaveblock relative toi-the'upper or;.'ireeaen,d of

the davitvbeam withlthe nayedoutfa 1. 11113 I0 running over the pulleys I:I:-;'I16; I15; ,I3.;and l9 and through-:the sheavegblock. 'Ij-hus,;,the boat I3 is lowered to the iwatenand launched.

:Inraisingtheboatfrom-,thezwater; the beam I is initially in its full-y: exte.nded or-;.e.xtreme;;out-

II, It and I1 and of'thesheaveblock-from which the boat I3 is suspended is-preferably-greater than the frictional resistance to sliding-movement of the member -3' along-the beam 1" fora purpose that will appear hereinafter 'in the description of the operationo'f' the" boat-davit embodying the'invention.

The boat davit further includes a lever'member having two angularlyrelate'dintegral "arms 8 and 9 which is rockably mounted at the junction of its'arms' for' tu'rning about the-axis 2.

Thearm 8,-at its 'outboardor free end-is formed to bear the keel I2 of the supported boat I3, and the arm 9, at its'-free-' end, -isiormed topress against the beam I in the outboard direction to 'urge the davit beamto"swing-'outwardly in re- 2 sponse to the weight of the" boat up'on the arm 8. Thus, when the fall or line I0 is releasediwith the 'boatsupported as i'n Fig. 1; the weight of lowered for attachment to the boats As theuline I0 is reeled in;thesheavebloekjs aised and the weight of the.boat-,,.causing. a; ;tu;rning,,moment about the" axis 2 111 1 the clockwise direction as '-viewed in Fig. '5, retainsthe davit, beam its extreme outboard position-.59 that: thfipboat clears the side ofthe'ship; Only aftert-he sheava-biock I has beene-iully raised. andI-afurther m evengent thereof toward the pulley 1H seimpossible gwill reeling in :of thefall or.;lin,e

of the davit beam in the inboard; inboard swinging is caused by, the; pull; exerted on pulley I8 by the line-.Imwhich reduces the .dis-

'tances between the axis of the pulley lagand the P axes of the pul1eys-: I.l.;and;.I9and-therebyswings I with the resultant'inward swinging-5 of thesdavit beam; As the; concluding phase 'of the inward swinging of the 'davit beamqiscompleted; theiarm 8 is rocked upwardly ."by thecbeam actin against thetrestle 4 inwardly :to effect movementor the slide: member ;,3 upwardly along the davitbeam I thearm 9rtoengageiunder thekeel; I lief theib t so that the davit and boat are again in" their relative positions shown in Fig. 1.

From the foregoing description it is apparent that the present invention provides a boat davit in which the beam I may be of relatively light construction by reason of the factthat the slide member 3 progresses toward the free end of the beam as the latter swings in the outboard direction and the trestle 4 acts as a jury strut and serves to support the beam l so'that the bending stresses in the latter do not become excessive. Further, the triangular configuration of the trestle 4 provides lateral support for the davit beam thereby reducing lateral loads on the latter even when the vessel is pitching severely. It should also be noted that the fall or line l0 leaves the davit, as at 20, closely adjacent to the deck so that it does not interfere with the movements of crew or passengers in the area of the davits during the launching of the boats, and that the lever member comprised of the integral arms 8 and 9 ensures the movement of the davit to its launching or outboard position even when the vessel is on its beam ends or listing severely.

Having described a preferred embodiment of the invention by way of illustration, it is to be understood that the invention is not limited to this precise embodiment, and that changes and modifications, obvious to one skilled in the art, may be effected therein without departing from the scope of the invention as defined in the appended claims.

I claim:

1. A boat davit comprising first horizontal pivot means mounted adjacent the side of a ships deck, second pivot means disposed inboard relative to said first pivot means and having an axis parallel to the latter, a supporting beam pivotally mounted at its lower end on said second pivot means for swinging in a vertical plane, said beam being longitudinally bent in the outboard direction so that the free end thereof is adapted to lie in the longitudinal medial plane of a boat supported in the davit when said beam is in an inboard position, a triangular trestle mounted at its base on said first pivot means, means pivotally mounted on the apex of said trestle and movable along said beam, said last mentioned means being permanently connected to said beam so that the swinging movements of said beam and said trestle about the respective pivot means are interdependent, spaced apart stop means on said beam in the path of said movable means and engageable with said movable means for limiting the swinging movements of said beam in both the inboard and outboard directions, lever means con-' structed and rockably mounted for engagement under the supported boat in the rest position of the latter and engageable with said supporting beam to induce initial swinging of said beam in the out-board direction in response to the weight of the boat bearing on the lever means, and rope and pulley means operatively connected to said trestle and beam for supporting a boat from the free end of the latter and for controlling the position of said trestle relative to said beam.

2. A boat davit as set forth in claim 1, wherein said lever means inducing the initial swinging of said beam in the out-board direction includes a lever member formed with two angularly related arms pivotally mounted at their junction on said second pivot means, the free end of the arm extending in the out-board direction being formed to bear the keel of the supported boat and to resist lateral movement of the boat toward said beam, the other arm of said lever member having its free end formed to press against said beam in the out-board direction to urge said beam in that direction in response to the weight of the boat upon the first mentioned arm and so that rotation of said beam and trestle in the outboard direction may continue even after the swinging of said first mentioned arm has been arrested.

3. A boat davit as set forth in claim 1, wherein said rope and pulley means includes a, first pulley rotatably mounted on said beam adjacent said free end of the latter, a second pulley rotatable on said beam at a predetermined distance inboard from said first pulley, a third pulley rotatable on said beam adjacent the pivoted end thereof, a fourth pulley rotatable on said trestle adjacent the apex of the latter, a fifth pulley rotatable about said second pivot means, and an elongated flexible rope member fixed at one end to said free end of the beam and then passing successively around the support pulley of the supported boat, said first, second, third, fourth and fifth pulleys so that said rope member leaves the davit adjacent the deck.

4. A boat davit as set forth in claim 3, wherein said pulleys are provided with an aggregate resistance to turning which is greater than the resistance to movement of said means movable along said beam so that relaxation of the tension of said rope member will initially cause out-board swinging of said beam and then lowering of the supported boat.

5. A boat davit comprising, in combination, an up-standing davit beam bent longitudinally in the outboard direction, means for mounting the lower end of said beam adjacent a ships deck for pivoting movement in a vertical plane between inboard and outboard positions, a substantially triangular trestle having its base end pivoted adjacent the deck for swinging about an axis which is outboard of and parallel to the pivoting axis of said beam, a slide-block pivotally connected to the apex of said triangular trestle and having a sliding connection with said beam throughout the movement thereof, and a lever having two angularly related arms and pivotally mounted at the junction of said arms coaxially with said beam, the free end of one of said arms having means extending therefrom to contact the inboard side of said beam, the outer end of the other of said arms having means thereon for supporting the keel of a boat, the angle between said two arms being such that, when the davit beam is in the inboard position, the weight of a boat bearing upon the outer end of said other arm will cause said means extending from said one arm to bear against the inboard side of said beam and in itiate rotation of said beam to the outboard position.

6. A boat davit comprising a davit beam pivotally mounted at one end adjacent the side of a ships deck for swinging in a vertical plane between inboard and outboard positions, a trestle member pivotally mounted at one end for swinging about an axis which is outboard of and parallel to the swinging axis of said beam, means movable along said beam and connecting the other end of said trestle member to said beam, fall and pulley means operatively connected to said trestle member and beam for supporting a boat from the free end of the latter and for controlling the position of said trestle aemsm 7 member relative te said beam, and a; Ievie'r 'mem-- ber having two angularly related armsv and pivotally mounted at the junction of said arms for rocking aboutthe swinging. axis. of said beam, the free end of one of said arms being formed to bear the keel of a supported boat when said beam is inlsaid inboard position, the free end of the other of said arms being formed to press against said beam in the outboard direction in response to the weight of the boat upon said one armto thereby initiate, swinging of said beam in the outboard direction.

I DOMENICO BARRICELLI.

References Cited the fileiof'this patent UNITED STATES PATENTS Number Number Name Date Mallery Sept. 17, 1872 McKenzie. Oct. 13, 1931 McKenzie Oct. 13, 1931 Hunt Jan. 24, 1933 Young Dec.v 3,, 1935 Hunt. Oct. 17, 19.44

FOREIGN PATENTS Country Date Great Britain Dec. 31, 1931 

